Method of forming cork disks and gaskets and product of the same



Feb. 19, 1929. 1,702,600

W. F. GRUPE METHOD OF FORMING CORK DISKS AND GASKETS AND PRODUCT OF THESAME Filed Aug. 10. 1926 Fig. l H

ENTOR M ATTORNEY Patented Feb. 19, 1929.

UNITED STATES PATENT OFFICE.

WILLIAM F. GRUPE, OF LYNDHITRST, NEW JERSEY, ASSIGNOB T0 BOUCHER CORKCOMPANY, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD OF FORMING COR-K DISKS AND GASKETS AND PRODUCT OF THE SAME.

Application filed August 10, 1926. Serial No. 128,481.

This invention relates to a method of forming cork disks and gaskets andthe product of the same.

It is wellknown to those skilled in the art that such crown caps aresubstantially circular in form and are made of metal by punchingoperation. lVithin the seat of the crown cap, cushions of natural corkand of composition cork have heretofore been employed to serve as thesealing medium. However, in View of the continued high demands fornatural cork for caps and other sealing purposes, and particularly inview of the restricted availability of less than twenty-five per centimposed by nature of natural cork of the required quality capable innatural state of effecting perfect sealing, the attempt has been made toemploy sealing disks of composition cork in substitution of naturalcork. However, when composition cork (which is formed of cork granulesbonded to one another by adhesives such as adhesives containing albumen,casein and the like) is brought in contact with the fluid contents ofthe bottle, the adhesive of the above nature is subject to decompositionand putrefaction, attended by discoloration of the cork due to theresulting chemical action, and consequent pollution of the contents ofthe bottle.

It has also been proposed to employ a collet of waxed paper or the likeinterposed between the disk of natural cork and the metal cap, but suchprocedure involves additional expense in material and in the assembly ofthe cap, and also gives rise to the penetration of the liquid throughthe pores and thence through the cork disk to the paraflin of the colletor to the paper itself where paraffin is not employed, and thus theflavor or odor of bottled contents is contaminated.

It has also been proposed to apply a sheet of lead or other metallicfoil on the outer face of the cork disk, but this procedure enburdensthe cost of additional material and the labor and machines for applyingthe metal foil to one face of each cork disk; furthermore the metal foilreduces the sealing quality of the cork disk since the metal foil isinterposed between the lip of the bottle and the cork disk.

The present invention is directed to the production of products of corkor like material, particularly from cork waste, whereby the product issubstantially free from pores inherent in natural cork and possesses thecharacteristics of sealing and like properties of natural cork, andbonded together autogenously and without the use of any adhesive of thecharacter heretofore employed.

The present invention is particularly useful in the production ofcushions of the disk and other forms for crown caps, also for gasketsfor automotive engines and general sealing uses, and are also applicablefor other uses in which natural cork is at present employed.

Pursuant to a preferred form of my invention for use as sealing cushionsin crown seals for bottled beverages and for use as gaskets in theassembly of scaled motor parts, the aforesaid products are formed bycharging into a mold of suitable contour particles of cork to thedesired amount, subjecting the charge to the desired compression as byreducing the volume of the charge within the mold and then subjectingthe compressed charge to an elevated temperature by applying thetemperature solely on one side of the mold, that is to say, on one faceof the charge, to thereby effect an increased baking effect on the corkparticles at and closely adjacent such one face and securing a bakingeffect at and through the remainder of the charge sufficient to bind thecork particles to one another and close the pores of the cork particlesand the interstices between the cork particles. The resulting productcomprises a mass por tion at one face of which the baking heat has beenapplied and constituted of cork substantially devoid of pores or otheropenings and devoid of clearances between the cork particles and whichmass possesses a limited extent of resiliency or yieldability. The massportion at the opposite face of the cork product is also devoid of poresor other openings and devoid also ofanyclearancesbetweenthe corkparticles and possesses a resiliency and yieldability of the charactercomparable to that of natural cork of the higher grades.

By the above procedure, the molded product may be inthe form of a sheet,from which are punched in the usual manner circular disks or other formsof sealing media for crown caps and closures for bottles and othercontainers.

Gaskets of the desired configuration and provided with the usualopenings for the reception of bolts and for affording communication forthe requirements of a motor, as for gasket use between a carburetor andthe endetermined by the e compression is the use to which the res gineinletmanifold or between the part-s of the Water cooling system orbetwee: the top or other plate and the body of the cylinders and allother gasket applications.

Further features and objects of the invention will be more fullyunderstood from the following detail description and the accon1- panyingdrawing, which Fig. 1 is a central, vertical section of a diagrammaticform oi mold showing the stage of subjecting the compres ed charge to abaking temperature pursuant to my invention;

Fig. 2 is a perspective view showing a portionof'a mold sheet from whichcircular cushion disks are being punched; and

3 is a detail sectional view on line 3 3 of Fig. 2. 7

Referring to Fig. 1', the mold l0 of any desired shape and oi? any desiid 'ormation. The type of mold illustrated in l; l of a simple formserving for the product of a sheet of the thickness con'iparabl thatfor'forming circular disks :lor crown caps for sealing beverage bottles.

For simplicity of illusti shown in Fig. 1 may be pro to. upper or hopperportion 11 into wl cor: particles are charged. The compie sion of thecharge may be eli'ected by me n of the pressure plate 12, freely littiwithin the four sides of the mold and su a hydraulic or other pressuredot. quantity of the char sired which may range il' finl a re I volumefrom two volumes to one volume and from six volumes to one volume.

A factor in determination of the extent of product is to be applied.Generally speaking, the extent of compression dctermi I degree of lifeof the resulting pi'odut.t particularly at the face of the product whiclsubjected to the lower temperature as will appear more fullyhereinafter.

Upon compressing the charge 13 to the desired extent, the compressionplate 12 is retained in position by any suitable means as by one or morebars 14: passing through o positely disposed openings: l5, 16 in thesides ill 18 of the mold hopper 11. Such procediu'e correspondsgenerally to steps of charging the mold and compressing the charge asset forth in my copending application entitled Separators lior storagebatteries, Serial No. 749,396 and tiled by me on the 19th day ofNovember, 1924.

The nature of the charge may any suit able form of cork. For commercialr sons, cork waste is desirable by reason of low cost of production; andby reason of a so of availability as a by-product attenoing tl emanufacture or" the commercial forms of cork at numerous locations otherthan the moaeoo pet's ."an'ulation of the left-over port-ions of sl e soi natural cork from which seahng ks or gaskets or the like have beenpunched or cut. Cork waste also includes so-called cork wool and theunused portions of thin shee s of natural cork from which cigarette tipsand the like have been sliced or cut.

The balt'ag is carried out by means of any form of heating capable oiattaining the desired temperature of baking. For the manufacture ofsheets of a. thickness suitable for forming sealing disks and motorgaskets, the heating element is preferably of the electrically heatingtype as is indicated 19, usually comprising a block of vitreous or aricial stone composition, in which is posiied or n'iolded an electricalresistance Wire 520 embedded in finely divided insulating ia 521, aswill be understood. by those l in the art.

Upon applying the heating face 22 01 the heath l 19 to the under face 23of the block old ii) the baking heat applied directly .e lower massportion 24 of the charge 13. should be observed that cork possesses ahigh cocllicient of heatinsulation and acl y the rate of conduction ofheat enoi ah the cork charge is low, which .06. effects a baking to ahigh degree of the lower mass portion of the charge 18. Such bakingtemperaturm however, is insuflicicnt to cause any substantial charringof the lower mass portion 24.

The range or baking temperature is deent upon the period of baking andthe d oi 1) 'ng is in turn dependent upon 0 cl, within which range tile4 ,o-it the resins inherent in cork or the adt 1d resinsot similarnature takes place and effects the spaced localization by the resins onthe surface of the cork particles.

The general cliect of the baking pursuant to my my on is indicated in 3.The

lower mas. portion @4- assumes a. decided darkened a apearance as aresult of the baking. Clhe structure of the lower mass portion. 2% issubstantially that of the nature of The constituency of the mass portion25 at and adjacent the upper and less baked face of the, molded productis that of a cork mass having the full life of natural cork of thehigher quality, namely, having the properties of resiliency and ofpermanence of formation and other characteristics of natural cork of thehigher quality, affording repeated use as a sealing medium. The outerface of the mass portion 25 is wholly devoid of pores and the clearancesbetween the original particlesare eliminated by the baking, which resultis comparable to autogenous welding of metals. It will be appreciatedthat in the simultaneous baking and compression of the cork charge, theresins inherent in natural cork are distilled at the successivelyincreasing temperatures corresponding to their temperatures ofvolatilization, and that the relutively tougher portions of natural corksuch as the walls of the original cells are gradually broken down as thetemperature increases. The distribution of the distilled resins throughthe mass effectually closes the pores of the cork particles and thisaction takes place within the intermediate portion and the uppermostportion of my product where the temperature is not sutlicient to producethe nature of solidification of the lowermost portion 2-l It will heobserved that such resins are wholly inert and wholly immune towardwater, beverages and including any alcoholic content, and for thepurpose of the present invention are highly advantageous in that no odoror flavor of whatsoever character is imparted to the contents of thebottle.

If desired, rosin or other resin of the nature of resins natural incorkwood may be added to the charge.

As is indicated in Fig. 2, the resulting sheet 30 is punched to formcircular or other shapes of disks 31 of'the proper diameter to serve assealing disks in crown caps or the like. The punching openings areindicated at 32, 33. In a similar manner, gaskets for automobile partsand for general gasket use may be punched from such sheets 30.

In the use of disks or other forms of my product for bottle sealingcushions the disks may be steamed or boiled to remove any loose orcharred portions, and also to wholly eliminate all tendency to leave anydark soot on the fingers of the operator when handling the disks or onother materials with which they are brought into contact.

By selecting the depth or other corresponding dimension of the mold toconform to the dimension of the resulting baked product, the oppositefaces of the product are therefore molded, that is to say, the materialat each molded face possesses a continuous surface of cork and bondedcontinuously and substantially uniformly by the resin inherent in corkwhen such resin is used alone as the binder, or by such cork resintogether with any additional resin added to the charge of the mold. Thematerial at such molded sur faces has a texture comparable to that ofleather, that is to say, resists mechani'al abrasion and has anincreased resistance against permeation by liquids, moisture,lubricating oils in liquid or vapor form and the like as compared with asurface formed by severing the molded product.

lVhereas, I have described my invention by reference to specific formsthereof, it will be understood that many changes and modifications maybe made without departing from the spirit of the invention.

I claim:

1. The method of forming baked, compressed cushions, gaskets and likeproducts of cork, which comprises compressing cork particles in a moldto a desired shape, baking the compressed cork particles by applying ahigher temperature to one side of the mold than on another side of themold, said higher temperature being capable of effecting thevaporization of the resin inherent in the cork particles, and formingthe product from the resulting baked product.

2. The method of forming baked, compressed cushions, gaskets and likeproducts of cork, which comprises compressing cork particles in a moldto a desired shape, baking the compressed cork particles by applying ahigher temperature to one side of the mold than on another side of themold, said higher temperature being capable of effecting thevaporization of the resin inherent in the cork particles, and formingthe product from the resulting baked product by punching operations.

3. The method of forming baked, compressed cushions, gaskets and likeproducts of cork, which comprises compressing cork particles in a moldto a desired shape and of a thickness substantially that of the desiredproduct, baking the compressed cork particles by applying a highertemperature to one side of the mold than on another side of the mold,said higher temperature being capable of effooting the vaporization ofthe resin inherent in the cork particles, and forming the product fromthe resulting baked product.

4. The method of forming baked, compressed cushions, gaskets and likeproducts of cork, which comprises compressing cork particles in a moldto a desired shape and of a thickness substantially that of the desiredproduct, baking the compressed cork particles by applying a highertemperature to one side of the mold than on another side of the mold,said higher temperature being capable of effecting the vaporization ofthe resin inherent in the cork particles, and forming the product fromthe resulting baked product by punching operations.

5. A cushion, gasket or like product formed of compressed cork baked atone side to a greater maturity than on the opposite side, the materialat-said opposite side being of greater resiliency than the material atsaid one side.

6. A cushion, gasket or like product formed of compressed cork baked atone side to a greater maturity than on the opposite side, the materialat said opposite side being of greater resiliency than the material atsaid one side, the opposite faces of said product being molded.

7. A cushion, gasket or like substantially fiat product formed of baked,compressed cork particles, the resiliency at one flat face being greaterthan the resiliency at the opposite flat face.

8. A cushion, gasket or like substantially fiat product formed of baked,compressed cork particles, the resiliency at one fiat face eing' greaterthan the resiliency at the oppo site fiat face, said flat faces being ofmolded forn'iation.

in testimony whereof I have signed this specification this 9th day ofAugust, 1926.

\VILLIAM F. GRUPE.

